Controller for electric motors.



F. W. LACEY.

CONTROLLER FOR ELEOTRIG' MOTORS.

APPLICATION FILED MAR. 2, 1910.

Patented Oct. 31, 1911.

INVENTOR WITNESSES:

ATTORNEY COLUMBIA PLANOGRAFH c0, WASHINGTON. u, c.

UNITED STATES PATENT OFFICE.

FREDERICK W. LACEY, OF BOURNEMOUTH, ENGLAND, ASSIGNOR TO WESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

CONTROLLER FOR ELECTRIC MOTORS.

Application filed March 2, 1910.

Specification of Letters Patent.

Patented Oct. 31, 1911.

Serial No. 546,854.

To a l whom it may concern:

Be it known that I, FREDERICK VVILLiAM LACEY, a subject of the King ofGreat Britain, and a resident of Bournemouth, Hampshire, England, haveinvented a new and useful Improvement in Controllers for ElectricMotors, of which the following is a specification.

This invention relates to controllers for the motors of electricallypropelled railway vehicles and particularly to that type of controllerhaving main and reverser drums, the latter of which is arranged to beoper ated by the initial movement of the former.

In controllers of the above mentioned type, which are now well known,the reverser handle merely serves to set a me chanical connectionbetween the two drums, so that, during the early part of the movement ofthe main drum from its off posi tion, the reverser drum will be moved inthe one or the other direction. It has been found in practice that it ispossible to move the reverser handle to its off position and to evenremove it altogether from the controller without the reverser drum beingnecessarily in the corresponding off position, with the result that thenecessary correspondence between the position of the reverser handle andthat of the reverser drum cannot be always insured. Under suchcircumstances, it may happen that certain contacts are left connectedwhich might lead to very serious accidents.

The present invention has for its object to provide an improved form ofoperating and interlocking mechanism for controllers of the kinddescribed in which the above disadvantages are avoided and in which itis impossible to move the reverser handle to its off position unless thereverser drum is also moved to a corresponding position, and also inwhich the latter drum is effectually locked in its off position, afterhaving been moved thereto. I

The invention is particularly applicable to controllers having operatingmechanism between the main and reverser drums of the kind set forth inUnited States Letters Patent 611,465, granted September 27, 1898 toWestinghouse Electric & lVlanufacturing Co, upon an application filed byHarry P. Davis, and it will be described, for the sake of convenience,as applied to such a controller.

In the accompanying drawings, Figure 1 is a plan view similar to Fig. 3of the drawings of the above-mentioned Letters Patent and Fig. 2 is aview in side elevation, partly sectional, corresponding to Fig. 2 of thedrawings of the said Letters Patent.

Reference may be had to the specification of the aforesaid LettersPatent for such description of structural details as may be desired inaddition to what is set forth herein.

Referring now to the drawings, the pinion 22 upon the shaft 4 of thereverser drum is adapted to be moved in the one or other direction bymeans of the racks 52 and 53 of the forked head 50, which is actuated bythe initial movement of the main controller drum shaft 8, in the mannerset forth in the above mentioned patent.

Vhen the reverser shaft is in the position shown in Fig. 1, which is theoff position, the tips of the teeth of the pinion 22 are in engagementwith the tips of the teeth of both the racks 52 and 53, and the shaftand its drum are thus locked against movement. It has been found inpractice, however, that accidental rotative movement of the reverserdrum is liable to occur, when the gear parts are in the positionsindicated, in case the gear teeth have become worn or in case they werenot accurately formed and adjusted before being placed in service.

In the preferred manner of applying the present invention to acontroller of the type illustrated in the drawing, the shape of the head28 is so modified as to comprise an extension or quadrant 64 having aslot 65 of special form to receive a pin 66 which is carried by one endof an arm 67, the other end of said arm being pivotally mounted on thecontroller casing at 68. The arm 67 also carries a projection 69 whichis adapted to enter a notch 70 in the pinion 22 to lock the said pinionwhen the latter and its attached reverser drum are in the off position.The shape of the slot 65 is such that, when the head 28 is moved, bymeans of the reverser handle, into the one or other of its extremepositions, corresponding to forward or reverse direction of rotation ofthe motors, the pin 66 withdraws the projection 69 from the notch 7 0and thus unlocks the pinion 22 and allows it to be rotated by the one orother of the racks 52 and 53 in the one or other direction when the maincontroller handle is moved, in a f manner well understood. lVhen thereverser handle is in its oif position, the pinion 22 will beeffectively locked in a corresponding position, and, should the pinionand its attached drum be displaced when the reverser handle is in theone or other of its extreme positions, that is to say, when the pinion22 is unlocked by reason of the withdrawal of the projection 69 from thenotch 70, it will be impossible to return the reverser handle to its offposition since the project-ion 69 and the notch 70 will no longerregister with each other. In the event of such displacement takingplace, it will be impossible for the reverser handle to be returned toits off position or removed until the displacement of the pinion 22 hasbeen corrected.

It will be understood that any other suitable means for operating theprojection 69' for locking and unlocking the pinion 22 of the reverserdrum may be substituted for the pin 66 and the slot 65.

I claim as my invention:

1. A controller of the kind described provided with mechanismindependent of the main drum for locking the reverser drum in its offposition and for preventing the reverser drum handle from being returnedto the off position and removed except when said drum is in the offposition, substantially as described.

2. In a controller, the combination with a main drum, a reverser drumand interposed operating means for the latter, of means independent ofthe main drum for locking the reverser drum in its off position and forpreventing the reverser drum handle from being returned to the offposition and removed except when said drum is in its off position.

3. The combination with a reverser drum shaft having a pinion and anaccentuating head, a main drum shaft, a double rack for said pinion, andinterposed cam and lever mechanism, of a locking projection for saidpinion, and means for moving said project-ion into and out of lockingengagement as the reverser drum shaft is rotated.

4. In a controller, the combination with a reverser drum shaft having apinion, of means for imparting a limited rotative movement to saidpinion in either direction, a pivoted arm having a projection to en gageand lock said pinion in its off position,

and means operated by the reverser drum handle to move said pivoted arminto and out of locking position.

5. In a controller, the combination with a main drum, a reverser drumand interposed operating and interlocking mechanism embodying apositionaccentuating slotted head and a recessed operating pinion forthe reverser drum, of a pivoted lever arm having a pin and a projectionwhich are adapted, respectively, to cooperate with the head slot and thepinion recess to lock the reverser drum in its off position.

In testimony whereof, I have hereunto subscribed my name this fourteenthday of February, 1910.

F. LAGEY.

Witnesses CLEMENT GEO. HERNDON, J. A. INNES DUFF.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

